Travel To Health: Health Benefits of Heat Therapy

Fever—a Protective Mechanism

Getting a fever is no fun. You likely get chills, you sweat, and you’re just generally uncomfortable. You get tired easily and need to rest. But, fever isn’t the real problem. It’s a symptom of something else. You must treat whatever that is to relieve the fever.

We know scientifically that fever is a protective or defense mechanism.[10] When body temperature reaches 101.3^oF (38.5^oC), the immune system shifts into a state of alarm. At this temperature, the level of immune chemicals in the bloodstream doubles, and immune defenses throughout the body increase. Within 6 hours, almost every major defense within the immune system doubles its efforts.[9]

Heat by itself has an antiviral effect. When a container of human cells and rhinovirus was immersed in a 113^oF hot water bath, the heat suppressed the multiplication of the virus by 90%, but did not kill the human cells.[11]

Fever is usually triggered when monocytes meet pathogens and this results in an increase of IL-1,[12] which is what triggers the fever response since IL-1 is a pyrogen.[13] IL-1 is also involved in the activation of the cellular and humoral immune response against the pathogen.[12]

Fever promotes migration of leukocytes and neutrophils to the area where the pathogen is[10] and it activates T Cell function.[14] Genes involved in the activation of the interleukins have been identified. The most important pathway is the nuclear factor kappa B (NF-kB), which is responsible to activate IL-1, IL-6 and IL-8 and it has an effect on two other pathways—the p53 protein and the heat-shock factor protein 1 (HSF1).[15]

Traditional Heat Therapies

Historically, heat had been recognized for their beneficial effects. The following list shows how various cultures have used simple forms of heat as a way of both cleansing and healing.

Ancient Greek medicine
Roman hot sulfur baths
Finnish saunas
Japanese hot tubs
Native American Indian sweat lodges
Turkish hammam
Bhutan's unique hot stone baths

Sauna is probably the most studied thermotherapy treatment.[16] The person sits in a wood room with a heater (electric or wood) with rocks on top that provides the heat. The Turkish bath tends to be humid while the Finnish sauna has high temperature and dry air.[17]

The usual duration of the sauna among adults is between 5 and 20 min followed by a quick cool-down to stop sweating, studies show that the cool down stage increases WBC count.[19]Children also take a sauna once a week with their parents, at which time the baths tend to be shorter in duration (5–10 min) and with lower temperature.[20]

Potential Health Benefits

Most people's perception, spas or hot tubs can help blood circulation, can beautify the skin, promote good health. In the below, we also list other potential benefits of thermotherapy:

Potential prevention and treatment of mild coronavirus 2 infections

SARS-CoV-2 is a dangerous virus that has caused a world-wide pandemic. This virus, however, is susceptible to elevated body heat and elevated body heat also enhances the immune system. In [6], the researchers thus hypothesize that frequent treatments of heat followed by cold could be the effective first line approach in the prevention and treatment of mild coronavirus 2 infections.

In Finland and Estonia, sauna is part of the culture in these countries and it is practiced at least once a week among the population. There were lower number of cases or deaths reported in both countries than the rest of Europe. For example,

The average reported deaths from COVID-19 per 100,000 population were 18.3 ±23.4 in Europe without Finland and Estonia, 5.9 in Finland, and 5.2 in Estonia.[6]

It would be hard to compare worldwide data with other countries due to limited testing and reporting in other countries.[8] Nevertheless, the community use of heat treatments is consistent with a lower prevalence and a lower death rate from COVID-19.[6]

Figure 1. 3 types of strokes in brain (photo credit: slideshare.net)

"May" reduce stroke risk

Based on an observational study, researchers found that compared with people who took saunas once a week, those who took them two to three times weekly were 12% less likely to have a stroke. People who took saunas four to seven times a week reduced their risk for stroke by 62%.[3]

There are plausible reasons saunas might be protective. “Temperature increases, even of 1 or 2 degrees Celsius, can limit inflammatory processes in the body and reduce arterial stiffness,” said the senior author, Dr. Jari A. Laukkanen, a professor of medicine at the University of Eastern Finland. “It’s possible that steam rooms or hot tubs could produce similar results.”

May be beneficial to heart failure patients

Although sauna bathing causes various acute, transient cardiovascular and hormonal changes, it is well tolerated by most healthy adults and children. Some studies have suggested that long-term sauna bathing may help lower blood pressure in patients with hypertension and improve left ventricular ejection fraction in patients with chronic congestive heart failure (CHF).[16]

It also seems that sauna treatment may help improve clinical symptoms and hemodynamic parameters secondary to an improvement in the endothelial function of patients with CHF whose endothelial function is impaired.[18]

"May help to treat cancer patients

The Gorter Model[9] is designed to restore and enhance cancer patient's immune function, enabling the immune system to aggressively and effectively combat cancer cells throughout the body. It is created by Dr. Gorter, who himself is a cancer survivor, and used to treat cancer patients at the Medical Center Cologne in Germany.

In its cancer treatment protocol, therapeutic fever is used in combination with immune therapies that include interleukin, interferon, and various other treatments.

To reactivate the immune system in these patients, the Gorter Model uses a process of controlled fever referred to in the scientific literature as fever-range, total-body hyperthermia—a form of treatment in which the entire body is heated to a moderate fever temperature of approximately 101.3^oF (38.5^oC).

Warnings

Japan has a high temperature at the hot spring area, after bath stroke is particularly high.

Studies have shown that bath water temperature exceeds 42 ℃, decomposing enzyme inhibitors increase blood clots (plasminogen activator inhibitor) content, thus reducing the activity of enzymes break down blood clots, likely at midnight three to six infarction accidents.

Contraindications to sauna bathing include unstable angina pectoris, recent myocardial infarction, and severe aortic stenosis.[16]

Sauna bathing is safe, however, for most people with coronary heart disease with stable angina pectoris or old myocardial infarction. Very few acute myocardial infarctions and sudden deaths occur in saunas, but alcohol consumption during sauna bathing increases the risk of hypotension, arrhythmia, and sudden death, and should be avoided.[16]

In a Finnish sauna study on children aged from 0 to 15 years, symptoms were rare and were not serious. One of the commonly found disorder is atopic dermatitis. In half of the cases of atopic dermatitis, it became worse in the sauna.